I'm pretty neutral w/ folks nuking bosses. Been used to it. I know people don't like it. I just use a 2-3 star team for other people's raid bosses. When I'm doing my own raid boss, I usually hit request for my teammates or not (do it randomly) and use my 4 star team.

The nectar is pretty random for any level of boss. Sometimes, you will notice you get a lower amount of nectar for that exact level and then get a higher amount of nectar.